Fuel injection system



Jan. 27, 1959 s. E. ALDRIDGE v 2,870,759

FUEL INJECTION SYSTEM Filed Oct. 31, 1955 2 Sheets-Sheet 1 $972/LDe/DGE.,

IN V EN TOR.

Jan. 27, 1959 l S. E. ALDRIDGE FUEL INJECTION SYSTEM Filed oct. s1, 19552 sheets-sheet 2 37 l fdlff@ 3,4 f i I ////l//// 9 a!! 552%/ n-e/DQE,

IN V EN TOR.

United States Patent O FUEL INJECTION SYSTEM Seth E. Aldridge, LosAngeles, Calif. Application October 31, 1955, Serial No. 543,951

16 Claims. (Cl. 12S-140) This invention relates to an injection systemfor feeding fuel to the various cylinders of an internal combustionengine, typically a gasoline engine.

The general object of the invention is to provide an improved injectionsystem for injecting very accurately metered charges of fuel into thedifferent cylinders of an engine, at precisely predetermined timesduring the operating cycle of the engine. is an arrangement in which theamount of fuel injected upon each operation, as Well as the time ofinjection, can be easily regulated, and` can be rendered responsive tochanges in the speed and other operating conditions of the engine, tothus result in anextremely versatile and exible overall fuel supplysystem. At the same time, the injection apparatus may be designed to beeasily attachable to a conventional engine, and so constructed as to bevirtually leak-proof.

It has recently been rather Well established scientifically that a verylarge part of the air pollution in cities today results from poorcombustion of fuel in the engines of motor vehicles. This unburned fuelfrom the exhaust pipe of a motor vehicle reacts chemically with ozone inthe air to produce a very disagreeable type of eye-burning smog It hasalso been learned that by far the poorest combustion'and therefore thegreatest emission of unburned fuel occurs during deceleration. In orderto overcome this difficulty, a further object of the invention is toprovide an automatic control system which will function to completelyand automatically close olf the supply of fuel to the engine duringdeceleration. This-is effected by designing the device to automaticallyshut off the fuel when the engine intake vacuum reaches a predeterminedvery high value, such as occurs during deceleration. In addition toreducing air pollution, this automatic shut olf feature also results ingreatly increased fuel economy.

A system embodying the invention preferably includes a series ofreciprocating pumping units, preferably piston and cylinder units, whichpump fuel to the various cylinders respectively of the engine. Thesepumping units are actuable by a rotary cam structure, with the variouspumping units preferably being actuated by a single cam and beingdisposed at circularly spaced locations about the cam axis. In order toallow for regulation of the amount of fuel injected on each actuation ofeach cylinder, I find it desirable to use a second cam or cam structure,which adjustably limits the retracting movement of the pumping units, tothereby vary the effective stroke of the pumping units and consequentlythe amount of fuel pumped. This second cam structure may be mounted forrotary adjusting movement about the axis of the first mentioned cam, andmay be rendered responsive to variations in the air intake vacuum at theusual throttle controlled butterfly valve.

An additional highly important feature of the invention resides in aunique manner of supplying fuel to the intake sides of the variouspumping units. For this purpose, I prefer to mount the cam or cams andthe pumping units within a common housing, and to form in thatParticularly contemplated ice ' 2 Y housing a chamber or chambersfromwhich thepfunitsy take suction. The Icams may be isolated yfromthe'fuel chamber by a flexible diaphragm which allows for transmissionthrough the-diaphragm of the cam forces4 for actuating the pumpingunits. lThe fuelI chamber may'be disposed annularly about the cam axisand'fcams, with fthe diaphragm also being annular ner wall of thechamber. z.

The time of injection may-be adjusted vby rotarycadjustment of thedevice about the cam axis.` A governor or the like, responsive to thespeed of the engine, `may effect such an adjustment automatically, vandasimilar manual adjustment may be made independentlyl ofthe governor. i

The above and other features and objects'of the present t invention willbe better understood from thef following detailed description of thetypical embodiments illustrated in the accompanying drawings inwhich: f.v

Fig. l is an end view of an internal combustion engine which includes aninjectorV system embodying the invention; i Y

.Fig 2 is a fragmentary partially diagrammatic repre.-

v sentation of the injector system of Fig. 1;

Fig.`3 is an enlarged fragmentary horizontal section through the pumpingunit of the injector system, with the fuel regulating cam being shown ina position for-delivering a maximum charge of fuell to thecylinders; 'i

Fig. 4 is a fragmentary vertical rsection taken essentially on line 4-4of Fig. 3; and f Fig. 5 is a schematic fragmentary representation of avertical form of the invention.

Referring rst to Fig. 1, I have represented essentially conventionalinternal combustion engine, having the usual pistons 11 which areconnected vto and drive a main crank shaft V12. The valve actuating camshaft is shown at 13, being driven in the usualmanner in timed relationtothe crank shaft 12. The gasoline or other fuel is fed to thevariouscylinders of engine 10 by means of an injector pump unit 14 which ismounted at the upper side of the cylinder block and is driven Vby camshaft 13. The distributor 15 for controlling the liring of spark plugs16 maybe mounted at the upperside of injector unit 14, and be driven bythat unit. c

Injector unit 14 receives gasoline from fthe .usual fue pump 17 (seeFig. 2) through a fuel inlet line 18. The gasoline is discharged frominjector `unit 14 through a number of tubes or lines 19 leading to thevarious dilerent cylinders respectively of the engine. In Fig. 2, one ofthe cylinders is represented fragmentarily at 20, with the firingchamber having a lateral enlargement 21 into which the usual inlet valve22 actuated by'cam shaft 13 intermittently admitsair, and from which thesecond valve 23 discharges the gases of combustion at the appropriatetime. Line 19 admits fuel intothis lateralenlargement 21 of the tiringchamber, through an inlet check valve24, which includes a spring pressedball check valve element 25 engageable with a seat 26. Each of thevarious cylinders of engine 10 is provided .with an individual inletcheck valve of the type shown at 24, past which pumping unit 14 forces ametered charge of fuel during the period of air intake past valve22finto that particular cylinder. The ow of air to the cylinders iscontrolled by the usual throttle actuated butterfly valve 27 (Fig. 2),which is mounted for pivotal movement about an axis 28within an airsupply passage 291leading to the intake manifold of the engine. The airflowing to the engine through tube 29 'moves downwardly as shown in Fig.2.

As best seen in Figs. 2, 3 and 4, the fuel meteringinjector unit 14includes a rigid preferably metal cylindrical housing 30typicallycentered about a .vertically extending axis 31 and having anouter upstanding cylin' and forming alradially 'in-vv at 10 an drica'lside wall '32 and a horizontal bottom wall 33. Housing is covered 'atit's upper side by 'a horizontal top wall 34, which is removably andrigidly secured to theV main portion ofthe housing in any suitablemanner,` a's' `by ja :series of fcifr'cula'rly spacedattaching screws35. Anannul'ar gasket 36, formed of a material adapted to withstand thefu'el being handled, 'may be interposed between the c'over3'4 and sidewall 32v 'of the housing, to form a fluid tight seal between these twoparts. At a number ofl'circularly spaced locations, side wall 32 of thehousing ha's 'a series of vtubular inwardly projecting portions 37,which form cylinders within which the externally cylindrical outerportions 38 'of anumber of piston elements 39 are mounted forreciprocal' movement. These cylinders 37 and pistons 39 are disposedabout axes whichjexten'd radially outwardly from the main axis 31 ofthedevice.

i The radially outer ends of the bores within cylinders 37 are partially'closed by connector members 40, which are threadedly 'attachedfat 41 tohousing wall 32, and

ywhich are Connected at their outerends to the previously mentionedlines 19 leadingto the various cylinders. The attachmentof each line 19to its corresponding connector fitting 40 may be effected b'y means of asuitable threaded fitting 42with the joints between lparts 32, 40, and19 being fluid tightto prevent the discharge of any fuel from cylinder37 except through line 19. Each of the pistons 39 may be actuatedradially inwardly by means of la coil jspring 43, which may be containedwithinV a suitablev central recess 44 formed within the piston.

Qn theinwardj'str'oke of each piston 39, radially inwardly toward axis31,' thel piston draws a charge of fuel into `the corresponding cylinder37 from an essentially annular fuel supply chamber 45 formed in theouter portion `of, housingt30. lThe fuel from this chamber 45passesminto cylinders 37 through individual check valve units 46, whichmay consist of small tubular valve housings `47 threadedly connectedinto the various cylinders 37 at 48and communicating with the cylindersthrough passages 49. Each check valve housing 47 may contain arspringpressed valve element 50, which is adapted to allow the iiow of fuelinto cylinder 37 from chamber 45, while preventing a reverse flow of thefuel during the radially outward pumping stroke of the piston. Thatpumping stroke 'of the piston is of course effective to force a meteredcharge of fuel from cylinder 37 through line 19 andan associated valve24 into oneof the cylinh ders of the engine. n

Inwardly of the housing beyond cylinders 37, piston elements 39 haveinner externally cylindrical portions 51, which are slidably receivedwithin bores or openings 52 in an upstanding cylindrical rigid flangeportion 53 of the housing, to assist the cylinders 37 in slidablyguiding pistons 39 for the desired movement radially of axis 31. Theinner end surfaces 54 of these various piston elements 39 extendvertically and transversely of th'e pistons, and are engaged by acontinuously rotating cam 55, which turns about the vertical axis 31.Cam 55 is rotatably driven in timed relation to the rotation of crankshaft 12 and cam shaft 13, and for this purpose is rigidly attached to adepending shaft 56, which carries at its lower end a gear 57 engageablein driving relation with a gear 158 carried by cam shaft 13. Shaft 56 issuitably journalled for rotation about only a vertical axis, as bypassage through a tubular bearing portion 59 of housing 30, with anadditional bearing 60 being provided toward the lower end of shaft 56.The shaft 56 and its carried gear f57, as well as bearing 60 ifemployed, are removably insertible downwardly into a suitable recess 61in the cylinder block of the engine, andare withdrawable upwardly out ofrecess 61 and out of engagement with drive gear 158 when unit 14 iswithdrawn upwardly from its illustrated position of attachment to themotor. Cam 55 may have the horizontal cross section represented in Fig.3, this cam preferably having a vertically extending outer pistonengaging surface 156, which is cylindrical `and centered about axis 31except at the location of `a charge of fuel into the correspondingcylinder 47 past check valve 46.

The radially inner side of fuel supply chamber 45 (into which fuel owsfrom line 18) is defined by a exible `preferably resilient diaphragm 59,which extends upwardly at the radially outer side of rigid housing wall53. This diaphragm 59 is annular, and may typically be formed of asuitable rubber or rubber-like material which is adapted to withstand,without deterioration, contact with the fuel being handled. Neoprene isa preferred mlaterial for diaphragm 59. The upper annular edge portion60 of diaphragm 59 is annula'rly clamped between cover 34 and yhousingwall 53, in a relation forming a fluid tight annular seal between thesevarious parts. The annular lower edge portion 161 of diaphragm 59 mayextend into an annular recess 16..1 formed in partition 53, and may betightly but 'releasably clamped ink that recess by a removable clampingring or snap ring 63, to `form ran annular fluid tight seal betweenpartition 53 and the diaphragm for preventing the escape of any of thefuel `at the location of that seal from cham-ber 45.

Each of the pistons 39 extends through an opening 65 in diaphragm 59,and has an Iannullar groove 66 formed in its louter surface into whichthe material of the diaphragm extends. The material of the diaphragm isannularly bonded or vulcanized to each piston 39 Y within groove 66, tothus form la fluid tight seal between the pistons and diaphragm. Thus,pistons 39 are free for movement radially toward and away from `axis 31,as permitted by the flexibility of diaphragm 59, while at the same timediaphragm 59 effectively seals the radially inner side of chamber 45, tolthus isolate the inner cam chamber from the fuel chamber 45.

' Each time that one of the pistons 39 is actuated ontwardly by cam 55,the piston is moved to an extreme outer position which is determined bythe radius of the `peak portion 58 of cam 55. The amount of fuel whichis pumpedtby piston 39 on each actuation is regulated by controlling theinward retracting movement of the piston when it is released by cam 55.For this purpose, I employ a second cam 67, which is mounted forrotation about a bearing portion 68 of housing Si), and Whose rotation,like that of cam 55, is about axis 31. Cam 67 [has a series 'ofincreased diameter radially outwardly projecting rrises or camlugs 69,which coact respectively `with lugs 70 projecting downwardly from theinner ends of pistons 39, to limit the nadially inward movement of thepistons. The pistons may be suitably retained against rotation, as byscrews 1,39 connected into partition 53 and projecting downwardly intoaxial groove in the pistons. The inner cam engaging surfaces 71 of lugs70 may be curved cylindrically about la vertical axis, as seen in Fig.3, and the curvature of the valleys 72 between the successiveprojections or rises 69 of cam 67 may correspond substantially to thecurvature of lug surfaces 71. From these valley portions 72 of cam 67,the outer piston engaging surface of this cam may curve progressivelyoutwardly to maximum diameter locations 73. The .angular spacing of thevarious cam. projections 69 of vcam 67 of course corresponds to theangular spacing of pistons 39 'about axis 31, so tlhlat in' lanyparticular rotary position of earn' 67 realtive to' housing 30, thevarious cam projections '69 limit inward movement of all of t'hepistons39 at corresponding positions, so that all of the pistons will pumpequal charges of fuel into the various engine cylinders. Rotaryadjustment of cam 67 within housing 30 of course i.varies the positionat which each of the pistons 39 will engage the corresponding camprojection 69, to thus vary the length of stroke of the piston, and theamount of fuel pumped.

Cam 67 is automatically rot-atively adjusted about axis 31 by means of apair of pins 74 which are attached to cam 67 at diametrically oppositelocations, and project downwardly through a pair of slots 75 in bottomhousing wall 33, which slots extend arcuately about axis 31 to -allowfor limited rotary movement of cam 67 and pins 74 'about that axis. Thelower ends of pins 74 are in turn pivotally attached at 76 to -a pair:of horizontally extending and horizontally moving elongated arms 77,which are actuated by fluid pressure responsive diaphragms 78. Each ofthe diaphragms 78 is mounted within la conventional diaphragm valvehousing 79, and is exposed at its upper side to atmospheric pressure,and at its lower side to a pressure communicated through a line 80 or 81from the yair flow passage within tube 29. The line 89 may connect intopipe 29 at S2, downstream of valve 27, and preferably just beyond thelocation of an edge portion of that valve 27 in the idle or closed valvecondition of the engine. Thus, when the engine `is idling, and valve 27is almost closed, a pressure considerably below atmospheric pressure iscorn-municated through line 80 to the under side of diaphragm 78. Whenthe speed of the engine increases beyond idle, the pressure at 82increases, and the tendency to pull the `associated diaphragm 78downwardly is reduced. The line 81 leading from the underside of thesecond diaphragm 78 communicates with tube 29 at the upstream side ofbutterfly valve 27, and preferably toward the cen-ter of that tube, toactuate cani! 67 in accordance with the pressure at that location. Bothof the diaphragms 78 may be spring urged upwardly by suitablecoilsprings represented `at 84. As will be apparent from Fig. 2, t'he :twodiaphragms 78 buck each other, so that the actuation of cam 67 is aresultant of the forces exerted by the two diaphragms. The arms or rods77 connecting the diaphragms with pins 74 may have adjusting portionsrepresented at 85, for initially adjusting the effective lengths ofthese two rods.

For mounting housing 30 to the cylinder block, the housing may have alower annular radially outwardly projecting flange portion 86, (see Fig.4) which rests on, and is rotatable about axis 31 relative to, amounting ring 87. Ring 87 is itself rigidly attached to a cylinder block88, as by means of a series of circularly spaced screws 89. The annularportion 86 of the housing may be held downwardly against ring 37 bymeans of a series of circularly spaced screws 90, which extendvertically through openings in housing portion 86, and through a numberofcircularly spaced slots 91 which are formed in ring 87 and extendarcuatelyabout axis 31. As will be understood, the connection formed byscrews 90 is sufficiently loose to allow the desired rotation of housing30 about axis 31 relative to ring 87, during which rotation screws 90move arcuately within slots 91 within rings 87. In order to allow for asimilar rotary adjustment of ring 87, screws 89 may pass through arcuateslots 92 (see Figs. 2 and 4) in ring 87, so that upon loosening ofscrews 89, ring 87 may be rotated to a desired position, and thenretained in that position by tightening of screws 89.

The adjustment of mounting ring 87 is thus a manual adjustment which ismade upon installation of the device in a motor assembly. vTheadjustment of housing v30 relative to ring 87, on the other hand, may bean automatic adjustment, which is preferably responsive to variations inthe speed at which crank shaft 12 of engine is turning. For thispurpose, I may utilize a governor which is diagrammatically representedat 93 in Fig. 4, .and which is driven by the engine crank shaftthrough asuitable drive connection represented at"94.-'"The main body or housingportion of that governor. may be rigidly attached to ring 87, as by aconnection represented at 95, and the governor may include an elementrepresented at 96, which is movable relative to housing 93 in accordancewith variations in the engine speed. Element 96 is then connected tohousing 30, as' by attachment to an upwardly projecting portion of oneof the screws 90, to thereby rotatably actuate housing 30 about axis 31relative to ring 87r in accordance with speed. variations. Thisautomatic adjustment allows for variation of the timing of fuelinjection as the engine speed varies. Also, the manual adjustmentallowed by screws 39 permits an initial setting of the injection timing.

In some instances, it is contemplated that the spark controllingdistributor may be mounted to the upper side of a fuel injection unit14, -as seenin Fig. l. For this purpose, cam 55 may contain a centralnon-circular recess 96 in the center of its upper side, into which alower non-circular or splined portion 98 of the distributor drive shaft99 may project downwardly, through a suitable opening 100 in the centerof cover 34. In this way, distributor shaft 99 is rotatably keyed in xedrelation to injector camv 55, and `is thus driven in timed relation tothe engine crank shaft.

To now describe the operation of the formof invention shown in Figs. 1to 4, assume that the engine is running, and -that crank shaft 12 andcam shaft 13 are continuously turning in timed relation, with thevarious valves 22 and 23 of the different cylinders being actuated bycam shaft 13. During such operation of the motor, shaft 56 of theinjector unit is continuouslyy rotatably driven about vertical axis 31by the cam shaft, through the interengagement of gears 57 and 58. Suchrotation of shaft 56 correspondingly rotates cam 55, whose cammingprojection 58 successively engages the various pistons 39, and actuatesthose pistons radially outwardly away from axis 31. As each piston movesoutwardly, it pumps a metered charge of fuel from the correspondingcylinder 37 and through an associated line 19 into the Vcorrespondingengine cylinder 20 (past check valve 24). The timing is such as toinject the fuel during the air intake stroke of the engine cylinder, sothat the fuel isy drawn into the cylinder with the air. At the propertime, distributor 15 closes a ring circuit to the spark plug of thecylinder in question, to thus burn the fuel.

The amount of fuel injected upon each actuation of the .individualcylinders is determined bythe length of the radially inward returnstroke of pistons 39, as regulated by rotary adjustment of lcam 67. Thiscam adjustment iswin turnrcontrolled by the two diaphragms 78, which areresponsive to the variations in Vacuum at the ends of the lines and 81(Fig. `2). When the engine is idling, the pressure at the end of line 80is considerably below atmospheric pressure, to draw the associateddiaphragm 78 downwardly as seen in Fig. 2, and thus actuate cam 67 in acounterclockwise direction (as seen in Fig. 2). In the same idlecondition, the pressure to which the second diaphragm 78 is exposed atits underside through line 81, is not much below atmospheric pressure,so that the spring 84 beneath ,that` second diaphragm tends to urge itupwardly as seen in Fig. 2. In this idle condition, the position of cam67 is such as to allow a small flow of fuel to the engine.

When the operator actuates the accelerator to open buttery valve 27,such actuation of the-butterfly valve increases the pressure at location82, to thus cause a rise in the pressure at the underside of thediaphragm 78 which communicates with line 80. Also, such opening of thebutterfly valve results in a decrease of pressure at the end of line 81,with the result that cam 67 is turned in a clockwise direction (as seenin Fig. 2), and toward the maximum charge position of Fig. 3, toincrease the stroke of pistons 39 and thus .increase the amount .of fuelbeing lfed to the cylinders. vAs -will Abe apparent, th diapliragms 78and their lines 80 and 81,

well as connector -rods 77 and cam 67, may be so designed as to give anydesired amount of fuel to the en- :gine under lany predeterminedcondition, so that the entire system is thus rendered very accuratelycontrollable. As thespeed of the engine varies, governor 93 elfects anadditional automatic regulation, by varying the rotary position ofhousing 30, and thus varying the time of fuel injection, in accordancewith changes in the speed of the engine. It will of course be understoodthat the rotary regulation of cam 67 and housing 3d muy ce effectedmanually rather than automatically, if desired in a particularinstallation. Also, it will be apparent that lines 18 and 19 mustofcourse be sufficiently exible to allow the discussed rotary movementof housing 3d.

`Fig. 5 represents a slightly variational form of the invention, 4whichis identical with that described in Figs. 'l and V4, except as thelocation at which the metered fuel is injected into'th'e various'cylinders of the engine. More specifically, instead of being injecteddirectly into the combustion chamber as in Fig. 2, the fuel in Fig. 5 is"injected into the intake manifold 105 through check valves .24a'corresponding to the valve 24 shown in Fig. `l2. These check valves 24avare connected into the various branches 16 of the intake manifold atlocations closely adjacent tothe intake valves 107 of the variouscylinders, but upstream of those valves, so that as the -airfows fromthe manifold 165 into the cylinders, the :injected 'fuel has anopportunity to intimately mix with l"the iair.

Under 'some operating conditions, for example during rapid deceleration,it may lne-desirable to entirely close r'oi 'the supply of fuel to theengine cylinders. For this purpose, l `prefer to so form cam 67 that itspeak port-ion's 73 will have a radius from axis 31 which is at least as,great as, and desirably slightly greater than, the radius 'of peak 58on'cam 55. Thus, when peaks 73 are positioned to engage piston lugs 70,cam 5S can rotate withoutany actuation of the pistons, and no fuel ispumped. ADiaphragms 78 may be designed to Iactuate cam 67 to Lthis'position when the vacuum at point 82 (Fig. 2) is extremely high and thevacuum at line S1 is not very -great l(as occurs during deceleration,when vaive 27 is almost closed with the engine speed substantiallygreater than idle).

vI claim:

l. -A fuel injectionv system for an internal combustion vengine having aplurality of cylinders; said system including a body containing chambermeans into which Af'u'eliis fed, rotary cam means carried by the 'bodyand continuously rotatably driven in timed relation to the engine undabout an axis extending Vthrough the body, a :plurality of reciprocatingpumping units taking ,suc- -tion` from said chamber means and actuatedby said cam means to pump metered charges of fuel to said cylinders"respectively, and aflexible diaphragm forming a wall of said chambermeans for isolating said cam means from said fuel'and flexing `inaccordance with the actuation of `said pumping units by said cam meansto allow the 'transmission of pumping force therebetween.

2. A system as recited in claim l, including additional cam meansoperable to limit the returning movement of 'saidreciprocating pumpingunits after their yactuation by said rst cam means and adjustable tovary the effective stroke of'the units.

3; A fuel injection system for an internal combustion engine having aplurality of cylinders; said system including a housing, rotary cammeans rotatably driven relative to 'said housing in timed relation tothe engine arid-about an axis extending through the housing, saidhousing Vcontaining van essentially annular chamber extending about saidcam axis, an linlet for introducing -fuelvinto said chamberga pluralityof reciprocating pumping units'crried byithe 'body 'at locations spacedcircularlyabout saidraxis and actuable by said cam means'to take fuelfrom said chamber and discharge it in metered charges to said cylindersrespectively, and a diaphragm extending essentially annularly abo-utsaid axis between said cam means and said chamber and forming a flexible`inner wall of the latter isolating the fuel from said cam means andflexing in accordance with the actuation of said pumping units by saidcam means to allow the transmission of pumping force therebetween.

4. A system as recited in claim 3, in which said units includereciprocating pistons having inner extensions extending through andsealed to said diaphragm for actuation by said cam means.

5. A system as recited in claim 3, including additional cam meansoperable to limit the returning movement of said reciprocating pumpingunits after their actuation by said first cam means and adjustable tovary the effective stroke of the units.

6. A system as recited in claim 5, in which said second cam means arecontained in said housing inwardly of said diaphragm and are rotatablyadjustable about said axis of said first cam means.

7. -A system as recited in claim 6, including a support, means mountingsaid housing to said support for rotary adjustment relative theretoabout said axis, and means for rotatively adjusting said housingrelative to the support in accordance with variations in engine speed.

ld. An internal combustion engine having a plurality of cylinders, andhaving a fuel injection system for feeding fuel to said cylinders, saidsystem including a body containing chamber -means into which fuel isfed, rotary cam means carried by the body and continuously rotatablydriven in timed relation to the engine and about an ,axis extendingthrough the body, a plurality of reciproeating pumping units takingsuction from said chamber means and actuated by said cam means to pumpmetered charges of Ifuel to said cylinders respectively, and a ilexiblediaphragm forming a wall of said chamber means for isolating said cammeans from said fuel and flexing in accordance with the actuation ofsaid pumping units by said cam means to allow the transmission ofpumping force therebetween.

9. A fuel injection system for an internal combustion engine having aplurality of cylinders; said system including a housing, rotary cammeans rotatably driven relative to said housing in timed relation to theengine and about a predetermined axis, said housing containing a chamberextending about said cam axis, an inlet for introducing fuel into saidchamber, a plurality of reciprocating piston and cylinder pumping unitscarried by the body at locations spaced circularly about said axis andAactuable by said cam means to take fuel from said chamber and dischargeit in charges to said cylinders respectively, and a diaphragm extendingabout said axis between said cam means and said chamber and forming aexible Wall of the latter isolating the fuel from said cam means andiiexing in accordance with the actuation of said ypumping units by saidcam means to allow the transmission of pumping force therebetween.

l0. A fuel injection system as recited in claim 9 in which said cammeans comprise a rotary calm part contained within said body and havinga cam projection which is operable, as the cam part turns, to`successively actuate said pumping units, there being a rotary driveshaft connected'to said cam part and projecting to the outside of ythebody for continuously driving said cam part.

`respectively to the lcorresponding engine cylinders, and Adischargecheck valvesfoperable to pass fuelfr'om said se. t

lines into the cylinders but preventing reverse fuel ow. 13. A fuelinjection system as recited in claim 9, in

which said chamber and said diaphragm are both essentially annular.

14. A system as recited in claim 9, including a support, means mountingsaid housing to said support for rotary adjustment relative theretoabout said axis, and means for rotatively adjusting said housingrelative to the support in accordance with variations in engine speed.

15. A system as recited in claim 9, including an inlet check valveassociated with each of said pumping units and carried by the body andoperable to pass fuel from said chamber means into the cylinder of theassociated pumping unit but preventing reverse ow of the fuel, andseparate lines leading from said pumping units respectively to thecorresponding engine cylinders, and discharge check valves operable topass fuel from said lines into the cylinders but preventing reverse fuelow, said chamber and said diaphragm both being essentially annular andcentered about said axis.

16. A fuel injection system for an internal combustion engine having aplurality of cylinders; said system including a body containing chambermeans into which fuel is fed, rotary cam means carried by the body andcontinuously rotatably driven in timed relation to the engine and abouta predetermined axis, a plurality of reciproeating piston and cylinderpumping units taking suction from said chamber means and actuated bysaid cam means to pump charges of fuel to said cylinders respectively,and exible diaphragm means forming a wall of said chamber means at thelocation of each of said pumping units isolating said cam means fromsaid fuel and ilexing in accordance with the actuation of said pumpingunits by said cam means to allow the transmission of pumping forcetherebetween.

References Cited in the file of this patent UNITED STATES PATENTS1,954,712 Palmer Apr. 10, 1934 2,189,499 Trimmer Feb. 6, 1940 2,244,669Becker June l0, 1941 2,395,964 Fodor Mar. 5, 1946 2,660,992 Roosa Dec.1, 1953

